Conventional digital paper systems, which include a digital writing surface and a digital pen device, have become very popular. The digital pen device determines its location in real time on the digital writing surface, which may include a visible or non-visible digital pattern. The writing surface may take the form of a digital tablet or digital paper, for example digital paper made by the Anoto Group AB and having an ANOTO® pattern. Various types of conventional digital pen devices include, but are not limited to, the MAXELL® digital pen, the NOKIA® digital pen, the LEAPFROG FLYFUSION® digital pen, LIVSCRIBE® Pulsepen, the ANOTO® digital pen, and the LOGITECH® digital pen. Besides knowledge of placement location, some digital paper systems also maintain records of information like pressure or time as well as various “state” values such as color or width.
The digital pattern enables the digital pen to interact with printed content, text, lines, images, etc. which may take the form of spreadsheets, maps, AutoCAD layouts, etc. The printed content is overlaid on top of, or otherwise applied to the digital pattern, which allows the digital pen to “see through” the printed content and capture its exact position from the digital pattern. To provide accurate position information, the indicia, pixels or other marks that makeup the pattern must have the desired size and spacing, and they must not merge with other inked or otherwise printed (e.g. black) areas on the paper. The properties of the digital pattern are adjustable, for example size, spacing and/or blackness level may be controlled through printer language set. The level of adjustment may be different for different printers. A digital pattern that is printed too large generates a “grayed-out” effect and results in the pattern overtaking any printed content. If the pattern is too small it is unreadable by the digital pen, thus making the document digitally degraded or even unusable.
As briefly discussed above printers controlled with hardware and software that instructs the printer how to print content on a page. Examples of printer control languages are Adobe® PostScript® and Hewlett Packard's® Printer Command Language. Any of these instructions interpret content to be printed and convert the content into the dots needed to form an output which results in a printed document. In other words it allows for the control of any brand of printer by modifying the output to allow for printing of content and a digital pattern. Different printers generally have radically different settings and capabilities and therefore may need to be altered to successfully print content and a digital printer.